Page images

Symbiots of A. rsicus have been described in some detail by Cowdry (1925c,192‘6n., and by Jaschke (1933).

The subgenus Argas is tentatively definai as follows:

“Parasites chiefly of fowls. Marphological characters entirely of genus Ar as. Sutural line (i.e. lateral groove) encircling body. With a fla ened body flange nnrphologically differentiated dorsal... ly and ventrally by a row of quadrate cells or by fine striations or wrinkles; body shape elongate. Integument finely wrinkled; discs conspicuous, radially distributed; lacking ventral “paired organ". Hood lacking; nnuthparts posterior of anterior body nnrgin by a distance about equalling their own length. legs mderate; tarsal humps lacking".

§. reflexus was designated as the type species of the genus Ar as by Etreille (l8C2) and is so considered by Cooley and Kohls Fan) and by Pospelova..Shtrom (191.6) [Nuttall et al (l908) pre

ferred to use _.§. Ersicus 7. l_\.. reflexus would,_thTr'efore, also be the type species 0 t subgemls Egas.

The size of each stage and of each sex, engorged and unengorged, has been reported by Hooker, Bishopp, and Wood (1912) and by Campana. Rouget (1954).


A. rsicus is easily recognized by characters listed above for the subgenus Ar as , with the restriction that its dorsal and ventral periphery s marked by a row of quadrate "cells" (fine striations in 5. reflexus).


The male is seldom over 5.0 mm. long and has a semicircular genital aperture. The female measures from 4.0 mm. to 11.0 mm. long and has a narrow, transverse genital aperture.

N hs are similar to adults except that they lack a genital. aperture although advanced instars may have a shallow depression in its place.

larvae are nicely illustrated in various editions of .Brumpt's Precis.

[merged small][graphic][merged small]

L N 9 d‘ EQUATCBIA PROVINCE REBCRDS 2 1 1 Juba domestic pigeon cote Nov 1 Juba domestic pigeon cote Jan

These specimens were collected in 1949 and 1950 but subsequent. ly we have been unable to find the pigeon argas in Juba or elsewhere in the Sudan. These few may have been remnants of stragglers or of a small number of introduced individuals. If it is a normal inhab. itant of the Sudan, the pigeon argas is sporadic and rare here. No other specimens are known from the Ethiopian Faunal Region, except those reported by Rousselot (l95l,l953B) from French West Africa and one, possibly this species, from Kenya (Heisch 1951.3).


Ar as reflexus appears to be a Near or Midd1eEastern tick that as sprefi northward through Europe a.nd Southwestern Russia and eastward to India and elsewhere in Asia (the status of related species or subspecies in Asia requires further study). It may have been accidentally introduced into a few localities in the Ethiopian Faunal Region north of the Equator and to parts of the Americas. If so, transportation of infested domestic pigeons undoubtedly has been responsible for this range.

NGKTH AFRICA: EGYPT (El Dardiry 1935. Hoo straal 1952A. Taylor, Pork, Hurlbut, and Rizk 1956). AIGERIA Nuttall et al 1908. Neumann 1911. Presence not subsequently verified)-._ 'Z-Unknown in Tunisia (Colas.Belcour 1929B)_._7

WEST AFRICA: FREIIIH WEST AFRICA (Rousselot 195l,l953B from Bamako, Sdfianl.

[merged small][graphic]

Z-?KENYA: Heisch's (19548) specimen may represent a closely related species._7

NEAR EAST: A. reflexus has been reported from Palestine (Theodor I§§Z), Turkey Wogel 1927, Kurtpinar 1954) and Iran (Delpy

1947B). Its occurrence in intervening areas is to be expected.

FAR EAST: According to Sharif (1938), this tick, as variety indicus Uarfirton, is an important pigeon parasite all over India.

EUROPE: In Europe, A. reflexus is generally distributed and extends at least as far north as fienmark (Christiansen 1934). It occurs also in the British Isles. The Russian range of this tick is said to be confined to the Caucasus, Crimea, and areas bordering southern Europe (Pavlovsky 1948), but Olenev (l929A,B,C,l93lA,B,C) also includes Middle Asia and western Siberia. Oswald (1939) did not find the pigeon tick in Yugoslavia.

[ AMERICAS: Cooley and Kohls (191.4) list western United States and Colu-'1T1"b1a as collecting localities for ticks that they call A. reflexus but that show morphological differences of yet unknown importance as species indicators._7


Domestic pigeons are the chief host of A. reflexus and are mentioned by all authors. Man is frequently attacked, especially in the vicinity of long unoccupied pigeon cotes. Chickens, horses, and (in America, see above) wild birds such as the condor, swallow, and screech owl (Cooley and Kohls 1944) have been listed as hosts. In the laboratory, any usually available mammal may serve as host.

The literature contains numerous reports of A. reflewrus biting man and the painful sequelae of these attacks. Although the pigeon argas is mostly strictly associated with pigeons, the exigencies of its domestic existence drive it to attack persons, possibly more frequently than does A. Ersicus.


Early literature concerning the pigeon argas as a parasite of man has been reviewed by Nuttall at al (1908). More recently, Kemper (1934) attributed four cases in Germany to the effects of warm weather. Kemper a.nd Reichmuth (191.1) reviewed the literature a.nd reported over twenty attacks in Germany. They believe it possible that this tick might not be able to complete its life cycle on hu. man blood.

It is now evident that Porter's (1928) spirited account of “A. rsicus‘ in Calama, Antofagasta Province, Chile, must be referred to 5. reflexus (or to the American variant; see DISTRIBUTION above), as indicated in the following paragraph. Bites of these ticks were sufficiently numerous and painful for attention to be devoted to the matter in the daily press of the region. Specimens furnished parasitologists as the cause of this "grave molestatiod“ were iden. tified as A. pgrsicus. Concerning Porter's report, Kohls (correspondence) has provi e t e following note for inclusion here.

“Early in 1950, I received from Dr. Amador Neghme R.,
Chief Department of Parasitology of the Public Health
Service, Chile, four adults and a nmph (said to be) ArEas

rsicus, collected in the Province of Antofagasta at t e
Eown of Calama. This seems to be the only Chilean place
where this tick occurs, and is found in human houses and
in dovecotes. In reply to his letter, I said, “Study of
this material indicates that the ticks are not Argas persicus
but Ar as reflexus, ..... The only South American specimens
of reflexus that I have seen previously were collected in
chicken coops at Bogota, Colombia..... The Calama speci_
mens appear to agree in all particulars with reflexus
of the Old World and from Bogota except for the presence
of a few quadrangular plates interspersed with the striae
on the flattened margins. This difference could well be
due to variation and for this reason I would like to have
more specimens from Calama for study“. In response to
this I received eleven adults from Calama and twenty
adults and fifteen nymphs from Chuquicamata, a town about
twenty miles away. The source was not mentioned in either
case, but all the specimens proved to be the same as those
sent previously. In brief, these specimens from Chile
that I have seen are not Argas persicus but are probably
local variants of A. reflexus .


The subject of A. reflexus as a human parasite will be treated more fully in a subsequent volume of this work.

_ 77 _


The pigeon tick may remain unfed in or near pigeon houses for many months, or even for several years (Nuttall gt;§l 1908. Mayer a.nd Madel 1950). Feeding is much like that of A. rsicus, which attacks poultry, and is accomplished at night. _Donestic chickens are apparently considerably less liable to attack by"§. reflexus than are pigeons. Hiding places of these ticks are easily found in the cracks and crevices of pigeon cotes. The life cycle ap. pears to be much like that of £. rsicus. Restrictive and opti. mum biological and climatic factors have not yet been reported in literature. Females feed prior to oviposition, but according to

Schulze (l943B), males require only a single blood meal annually.

During the larval stage there is no urinary or fecal excretion (Enigk and Grittner 1952). Nymphs and adults immediately after feeding discharge a mixture of urine and feces, followed by further excretion the following day. The simultaneous deposition of urine and feces causes the rapid formation of a mguanocrystaf" in the viscous mass, thus frequently leaving a white center of uine sur. rounded by a dark fecal ring on the surfaces on which the substance has been deposited. (Note: Compare this type of excretion with that of Ornithodoros moubata). Adults deposit only urine for some two weeks after feeding, t en at long intervals a mixture of feces and urine. Four weeks after feeding, females begin oviposition, during which time no excretion is seen. Coxal fluid is seldom voided during feeding, but usually begins only following complete engorgement (Zuelzer 19208, and our own observations).


MAN: Human beings who ventue near occupied or long abandoned pigeon houses are readily attacked, and the ticks may invade nearby human habitations after pigeons have left their usual resting places. Pain or irritation may be felt for years after the pigeon argas has bitten. This species is incapable of transmitting spirochetes of African tick.borne relapsing fever (Borrelia duttonii).


PIGEONS: Squabs are especially susceptible to bites of this tick and adults too may suffer to the point of death by exsanguina. tion when their houses are heavily infested. The pigeon argas is of negligible importance in the transmission of Salmonella bacteria among pigeons but does transmit fowl spirochetosis, B. anserina (= B. allinarum). It is said to be probably capable of transmitting fowI piroplasmosis (Ae tianella pullorum).

- 78

« PreviousContinue »